Method of and apparatus for forming rolls of continuously supplied sheet material

ABSTRACT

Continuously supplied sheet material, e.g. synthetic-resin foils is wrapped around the upper of two vertically spaced cores as these cores are rotated about their axes. The two cores are then swung through 180* to move the upper core to the position of the lower core and vice versa, thereby stretching the sheet over a deflecting roller extending between a pair of mounting assemblies or stars (spiders) carrying these cores. The core then in the lower position is rotated until the outer surface of the roll formed thereon is immediately adjacent the upper core, whereupon the sheet is cut and the cut end is wound on the upper core. The lower filled core is replaced with an empty core and the mounting assemblies are again swung through 180*.

United States Patent Keferstein July 1, 1975 54] METHOD OF AND APPARATUS FOR 3152.412 8 1973 Byrt 242/56 A FORMING ROLLS OF CONTINUOUSLY SUPPLIED SHEET M TE L Primary Examiner-Edward J. McCarthy F. b [75] Inventor: Horst Keferstein, Mullekoven. Attorney Agent or Firm Karl Ross Her en Dubno Germany [73] Assignee: geifenhauser KG, Troisdorf, [57] ABSTRACT man er y Continuously supplied sheet material, e.g. synthetic- Flledi p 1 1974 resin foils is wrapped around the upper of two verti- [Zll APPL No: 459,049 cally spaced cores as these cores are rotated about their axes. The two cores are then swung through 180 I to move the upper core to the position of the lower Foreign Application Priority Dam core and vice versa, thereby stretching the sheet over A r, 6, 1973 Germany 2317325 a deflecting roller extending between a pair of mounting assemblies or stars (spiders) carrying these cores. [52] U.S. Cl. 242/56 A; 242/64 The core then in the lower position is rotated until the [5|] Int. Cl B65h 19/20; B65h 75/34 outer surface of the roll formed thereon is immedi- [58] Field of Search 242/56 A, 56 R, 64 ately adjacent the upper core, whereupon the sheet is cut and the cut end is wound on the upper core. The [561 References Cited lower filled core is replaced with an empty core and UNITED STATES PATENTS the mounting. assemblies are again swung through 2,943,806 7/1960 Phelps 242/56 A 180 3.207.452 9/!965 Haskin 7 3.635,4l5 1/1972 Phelps 242164 12 Drawmg F'gmes PATFNTFP JUL SHEET AT uTFnJULl SHEET .llllllJul J SHEET TFHE'FPJUL a SHEET METHOD OF AND APPARATUS FOR FORMING ROLLS OF CONTINUOUSLY SUPPLIED SHEET MATERIAL l. FIELD OF THE INVENTION The present invention relates to a method of and an apparatus for making rolls of sheet material. More particularly this invention concerns a system for winding continuously delivered sheet material, such as polyethylene film. into large-diameter rolls.

2. BACKGROUND OF THE INVENTION In the production of rolls of sheet material the rolling of the sheet material. the rolling of the sheet material up on tubular or solid cardboard or metal cores or the like as this material is continuously supplied from an extruding machine or the like presents a considerable problem. It is imperative that the continuously supplied sheets be wound up at a rapid rate without stopping the feed.

ln one known apparatus for carrying out this method a central shaft carries two oppositely directed pairs of outrigger arms between which cores are mounted. Both of these cores are rotated at a speed sufficiently high to wind up the foil or film as it is delivered to them. Film is wound around one of the cores until the outside of the roll approaches the rotation axis for the device. At that moment the entire apparatus is rotated through 180. the film is cut. and wrapping is continued on the new upper core. Meanwhile the completed roll is removed and an empty core substituted in its place.

Such an apparatus has a relatively limited capacity in that the maximum diameter of a roll can only be equal to twice the radial distance between the periphery of the central shaft of the device and the axis of the core. Thus a relatively tall piece of equipment must be used. thereby making it impractical to stack two or more winders for simultaneous operation.

Another difficulty is that it is necessary to provide heavy lifting equipment in order to remove the rather cumbersome rolls from the high machine.

3. OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide an improved method of and apparatus for forming rolls of sheet material.

Another object is an improved system for winding a continuously delivered sheet onto cores A further object is to provide a relatively small machine, especially low height, which is capable of producing relatively large-diameter rolls.

4. SUMMARY OF THE INVENTION These objects are attained according to the present invention in an apparatus of the above-described general type which does not have a central axis, but wherein the two mounting assemblies (stars or spiders) in which the ends of the cores are held are interconnected by a pair of elongated parallel deflecting elements which lie to either side of a core plane including the rotation axis of the apparatus and the axes of the core. Thus the sheet is wound around one of the cores until the outside of the roll passes well through the rotation axis of the device and approaches the other core. Thereupon the sheet is cut and the filled core is removed while the sheet is wound about the other core. Once a new core is fitted to the machine the entire assembly is rotated through a 180. with the sheet being deflected around one of the elements extending between the mounting assemblies and serving to link them rotationally together.

Thus it is possible to form a roll having a radial dimension considerably greater than the radial spacing between the rotation axis of the mounting assemblies and the core. Indeed in accordance with the present invention it is possible to form a roll having a diameter equal to half or more than the overall height of the machine. and making it therefore possible to stack such machines one atop the other.

According to the present invention the cores have axes which lie in a common plane with the rotation axis and at an angle of between 20 and 40. preferably to the vertical. The deflecting elements or idler rollers have axes which are also coplanar with the rotation axis and which lie in a plane perpendicular to the plane of the core axis. Therefore in accordance with the present invention it is possible to unload the filled core at the bottom of the device. The apparatus is dimensioned so that the spacing between the axis ofthe lowermost core and the floor is approximately equal to the spacing between this lower core axis and the outer surface of the upper core so that when the lower core is substantially filled, the roll has an outer surface closely approaching the upper core and very near the floor. Thus the machine operator need merely move one ofthe core holders axially outwardly so as to drop this filled core a short distance on to the floor. whence it can be rolled away.

According to yet another feature ofthis invention the spacing between the core axis is between one-third and two-thirds. preferably one-half. of the spacing between 5 the axes of the elements. These elements are deflecting rollers of cylindrical shape and serve to flatten the sheet and ensure a proper fold-free winding of this sheet onto the core.

Yet another feature of the invention resides in the provision of means for continuously feeding the sheet to the winding location including a feed roller above the mounting assemblies and having an axis parallel to the rotation axis thereof. The rotation axis of this feed roller and the rotation axis of the mounting assemblies 5 define a plane lying between and preferably 5. BRIEF DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more readily apparent from the following description. reference being made to the accompanying drawing in which:

FIG. 1 is a vertical section through the apparatus according to the present invention;

FIGS. 2 and 3 are cross-sections taken along lines lI-II and lines Ill-Ill of FIG. 1 respectively;

FIGS. 4 and 5 are side views similar to FIG. I illustrating the machine in two stages of its operation;

FIG. 6 is a side view illustrating the stacking of two similar machines as shown in FIGS. l-S; and

FIG. 7 is a view similar to FIGS. 4 and 5 indicating in enlarged scale further details of the apparatus according to the present inventionv 6. SPECIFIC DESCRIPTION As shown in FIGS. I3 the apparatus according to the present invention comprises a housing 2 to which is continuously fed a polyethylene film l. A pair of similar mounting assemblies (stars or spiders) 4 and 5 are rotatable on this housing 2 about a horizontal axis 3. Each of these assemblies 4 and 5 comprises a mounting unit 13 carried on a shaft 27 and each carrying a pair of cone holders 6 which define two axes A parallel to and equispaced from the axis 3 and spaced apart by a distance 15. One of the mounting units 13 is provided with a motor 28 which serves to rotate both of the cones 6 carried on the mounting unit. The shafts 27 are slidable in hollow shafts 9 which carry a pair of arms 12 between whose ends extend parallel rollers 8 which lie on axes A parallel to and equispaced from the axis 3 and spaced apart by a distance 14 equal to twice the distance 15. The shafts 27 are slidable within the shaft 9 so as to allow the assemblies 4 and 5 to be displaced between the solid-line position shown in FIG. 2 and the dot-dash line position. Thus an empty space is left between the mounting assemblies.

A motor 29 connected to the shafts 9 and 27 serves to rotate the assemblies 4 and 5 periodically about axis 3 through an are equal to 180. The axes A and 3 define a plane P including axes A and perpendicular to a plane I" which includes axis A and lies at an angle of 30 to the horizontal as is shown in FIG. I when the assemblies 4 and 5 are stopped.

The sheet I as shown in FIG. 7 is looped over a compensating roller [8 carried on arm 30 and adapted to swing about a horizontal axis A" so as to compensate for minor variations in rotation speed. Thereafter the sheet 1 passes over a roller 16 and between a pair of rollers 21 and 22 carried as shown in FIG. 7 on a pair of arms 23 pivotal about a horizontal axis 24 and con nected via another arm 25 to a hydraulic cylinder 26 which can pivot these arms 23 between the dot-dash line position shown in FIG. 7 and the solid-line position. The roller 22 has an axis A' which defines with the axis 3 an imaginary plane lying at 45 to the horizontal.

It is possible as sown in FIG. 6 to provide such machines one directly above the other. It will be noted in this arrangement that the apparatus has an overall height H equal to approximately ll; times the maximum diameter of a roll ll producible by the machine as will be described below.

the apparatus according to the present invention functions as follows:

To start with, two empty cores 7 are loaded between the two pairs of holders 6. The end of the sheet is looped under the roll 18, over the roll 16, and between the rolls 2l and 22 where it is applied to the uppermost roller. The motor 28 is then operated and the feeding of the foil is commenced. This causes the sheet 1 to wind up about the upper core 7. Thereupon the motor 29 is actuated to rotate mounting assemblies 4 and 5 about their axis 3 through 180 so that the sheel passes over one of the rollers 8 and is wound up on the core 7 in the lower position.

The sheet is allowed to wind up on this lower core until its outer surface very nearly approaches the upper empty core 7. The distance between the axis A and the lower core 7 and the floor 31 substantially equal to distance 15 so that as the outside of the roll comes close to the core 7, it also approaches the floor 31 as illustrated in FIGS. 4 and S.

Thereupon the cylinder 26 is actuated to draw the arms 23 down. This brings the roll 21 into contact with the upper rotating core 7 and at the same time brings a heated blade 19 carried by these arms 23 into engagement with that section ofthe sheet 1 extending between the roller 21 and the deflecting roller 8. At the same time a blast of air is emitted from nozzles 20 carried on the arms 23 so as to blow the cut end of the sheet I around the upper core 7, thereby causing the sheet to wind around this upper core.

The roll 11 is then released from between its two holders 6 and rolled away as shown in FIG. 5. A new core 7 is mounted between those lower holders 6 and the motor 29 is again actuated to swing the mounting assemblies 4 and 5 through and start the cycle over again.

It is possible with a machine according to this invention having an overall height H of 900 mm to form rolls having a diameter of 600 mm. Thus a very compact structure is provided. In addition the large cylindrical flattening rollers 8 insure that the sheet material is wound smoothly onto the core 7. These cores 7 may be replaced with solid steel shafts or similar arrangements as is well known in the art.

I claim:

I. An apparatus for forming rolls of a continuously supplied sheet, said apparatus comprising:

two mounting assemblies jointly rotatable about a rotation axis and carrying two pairs of holders defining a pair of parallel core axes parallel to said rotation axis and diametrically across said rotation axis from each other. one holder of each of said pairs being provided on each of said assemblies;

a pair of elongated parallel deflecting elements extending parallel to said rotation axis between said assemblies and lying to either side of a core plane including said rotation axis and said core axes;

means for rotating about said core axes cores carried on said holders and each lying along a respective core axis;

means for wrapping said sheet around one of said cores. whereby said sheet is wound up on said one core, and for cutting said sheet and wrapping same about the other core when said one core is filled, whereby said sheet is wound up on said other core; and

means for rotating said assemblies and said elements about said rotation axis through substantially 180" after cutting of said sheet and wrapping of same about said other core.

2. The apparatus defined in claim 1 wherein said core axes are spaced apart by a distance substantially smaller than the distance between said elements.

3. The apparatus defined in claim 2 wherein said elements have element axes defining with said rotation axis an element plane generally perpendicular to the plane of said core axes.

4. The apparatus defined in claim 3 wherein said elements are generally cylindrical idler rollers centered on said element axes.

5. The apparatus defined in claim 4 wherein said core axes are spaced apart by a distance equal to between one-third and two-thirds of the distance between said elements.

6. The apparatus defined in claim 5 wherein said assemblies each include a pair of oppositely radially extending arms. said rollers extending between said arms.

7. The apparatus defined in claim 6 wherein the holders of at least one of said pairs of holders are axially displaceable relative to the holders of the other pair.

8. The apparatus defined in claim 7 wherein said element plane lies at an angle of between and 40 to the horizontal.

9. The apparatus defined in claim 8 wherein the axes of said rollers are spaced apart by about twice the distance between said core axes.

10. The apparatus defined in claim 9 wherein said element plane includes an angle of substantially with the horizontal.

II. A method of making rolls of sheet material comprising the steps of:

continuously feeding an elongated sheet to a winding location;

winding said sheet at said location about an elongated first core by rotating same about its longitudinal axis; displacing said core through substantially about a rotation axis parallel to the axis of the first core while continuing to wind said sheet therearound; cutting said sheet and wrapping same around a second elongated core having a longitudinal axis parallel to said rotation axis and diametrically opposed to the axis of said first core when the sheet wound on said first core forms a roll extending past said rotation axis and approaching said second core;

thereafter winding said sheet about said second core by rotating same about its longitudinal axis;

thereafter removing said first core from said location. disposing another such first core in the place of the removed first core, and displacing the fresh first core and said second core through substantially 180 about said rotation axis.

12. The method defined in claim 9 wherein after winding ofsaid sheet around one of said cores. said one core is moved through 180 from an upper position to a lower position below said upper position, said core being removed while in said lower position 

1. An apparatus for forming rolls of a continuously supplied sheet, said apparatus comprising: two mounting assemblies jointly rotatable about a rotation axis and carrying two pairs of holders defining a pair of parallel core axes parallel to said rotation axis and diametrically across said rotation axis from each other, one holder of each of said pairs being provided on each of said assemblies; a pair of elongated parallel deflecting elements extending parallel to said rotation axis between said assemblies and lying to either side of a core plane including said rotation axis and said core axes; means for rotating about said core axes cores carried on said holders and each lying along a respective core axis; means for wrapping said sheet around one of said cores, whereby said sheet is wound up on said one core, and for cutting said sheet and wrapping same about the other core when said one core is filled, whereby said sheet is wound up on said other core; and means for rotating said assemblies and said elements about said rotation axis through substantially 180* after cutting of said sheet and wrapping of same about said other core.
 2. The apparatus defined in claim 1 wherein said core axes are spaced apart by a distance substantially smaller than the distance between said elements.
 3. The apparatus defined in claim 2 wherein said elements have element axes defining with said rotation axis an element plane generally perpendicular to the plane of said core axes.
 4. The apparatus defined in claim 3 wherein said elements are generally cylindrical idler rollers centered on said element axes.
 5. The apparatus defined in claim 4 wherein said core axes are spaced apart by a distance equal to between one-third and two-thirds of the distance between said elements.
 6. The apparatus defined in claim 5 wherein said assemblies each include a pair of oppositely radially extending arms, said rollers extending between said arms.
 7. The apparatus defined in claim 6 wherein the holders of at least one of said pairs of holders are axially displaceable relative to the holders of the other pair.
 8. The apparatus defined in claim 7 wherein said element plane lies at an angle of between 20* and 40* to the horizontal.
 9. The apparatus defined in claim 8 wherein the axes of said rollers are spaced apart by about twice the distance between said core axes.
 10. The apparatus defined in claim 9 wherein said element plane includes an angle of substantially 30* with the horizontal.
 11. A method of making rolls of sheet material comprising the steps of: continuously feeding an elongated sheet to a winding location; winding said sheet at said location about an elongated first core by rotating same about its longitudinal axis; displacing said core through substantially 180* about a rotation axis parallel to the axis of the first core while continuing to wind said sheet therearound; Cutting said sheet and wrapping same around a second elongated core having a longitudinal axis parallel to said rotation axis and diametrically opposed to the axis of said first core when the sheet wound on said first core forms a roll extending past said rotation axis and approaching said second core; thereafter winding said sheet about said second core by rotating same about its longitudinal axis; thereafter removing said first core from said location, disposing another such first core in the place of the removed first core, and displacing the fresh first core and said second core through substantially 180* about said rotation axis.
 12. The method defined in claim 9 wherein after winding of said sheet around one of said cores, said one core is moved through 180* from an upper position to a lower position below said upper position, said core being removed while in said lower position. 